Rethinking the Squeaky Pop Test-A Novel Hydrogen Test for Chemistry Classes

In school chemistry, the oxyhydrogenor "Knallgas"reaction is used to provide evidence of hydrogen gas in the squeakypop test. However, the test actually indicates the presence of anexplosive gas mixture of hydrogen and oxygen (oxyhydrogen gas) ratherthan pure hydrogen. The sheer observations of an explosive reactionand the formation of a condensing reaction product, which can be detectedas water, are not sufficient to call the squeaky pop test a clearand specific test for hydrogen. These observations can also be madeby burning gaseous hydrocarbons with stoichiometric amounts of oxygen,contradicting the assumption that the gas present in the reactionvessel is a mixture of hydrogen and oxygen. For a reliable detectionof hydrogen, this article presents the preparation of a heterogeneouscatalytic system which facilitates a specific and unambiguous hydrogentest in chemistry classes by using a redox dye for the clearly visibleindication of hydrogen: the Heterogeneous Catalyzed Hydrogen Test(HeCHT). The catalyst can be synthesized easily and safely due tothe low hazard potentials of the reactants and products. Furthermore,the preparation of the test reagent is inexpensive, and the reagentcan be reused.